Quote Originally Posted by bob k. mando View Post
sounds like you're vapor locking. ie - the fuel in the line is getting too warm and boiling off before it gets to the carb resulting in interruptions to fuel flow.

check all of your fuel line routing and make certain that it's well away from all exhaust components. use thick rubber hose in the top of the engine compartment.

you might try putting a wooden or plastic spacer under the carb, that blocks most of the heat conduction into fuel bowl from the intake manifold..

you might also try leaving the hood up or open if you're only going to park for a short time. that will help dump heat from the engine compartment.

Probably not vapor lock since vapor lock occurs on the suction side of the fuel pump. Any pump will push fuel and any vapor easily, but cannot pull vapor. Any 'treatments' between the fuel pump and carburetor are useless. When vapor lock occurs there is total lack of fuel after driving a a few hundred feet and the engine dies.
Most likely what is happening is percolation where the gas in the carb boils and dumps into the intake manifold. In the severe form the engine will appear flooded needing prolonged cranking when trying to start 30 minutes later or if set overnight the carb is dry and requires prolonged cranking to fill again; less severe will flood the air bleeds in the carb and there will be rough running a hesitation until that clears. A spacer under the carb will help with percolation.